基于遥感的东北植被物候沿城乡梯度变化  

Vegetation phenology changes along an urban-rural gradient in Northeast China based on remote sensing

作　　者：邱嘉琦 房磊[1] 杨健[1] 

机构地区：[1]中国科学院沈阳应用生态研究所,沈阳110016 [2]中国科学院大学,北京100049

出　　处：《生态学杂志》2017年第6期1699-1707,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金优秀青年科学基金项目(41222004)资助

摘　　要：植被物候沿城乡梯度的变化反映城市化过程对局地水热条件的调节作用。遥感技术可从区域和全球等大尺度上获取植被物候信息,从而弥补传统物候观测方法的不足。本研究以我国东北省会城市沈阳、长春、哈尔滨为例,基于MODIS NDVI数据,利用SavitzkyGolay滤波和分段高斯函数计算了各城区周边20 km内缓冲带的2种关键物候参数(生长季开始和结束日期);分析多年平均物候沿城乡梯度的变化,以及地表温度和林地盖度对物候空间变化的影响。结果发现:距城区越近,生长季开始越早,结束越晚,变化也越明显;在城乡梯度上,生长季随春季和前一年冬季地温升高而提前开始6~31 d·℃^(-1),随夏秋两季地温升高而推迟结束0.9~7.6 d·℃^(-1),而部分缓冲带内林地增多也会导致类似的生长季提前开始和延后结束。Changes of vegetation phenology along the urban-rural gradients can reflect how urban- ization regulates local water and heat conditions. Remote sensing can provide vegetation phenology at large scales （ e.g. regional or global）, making it a great alternative to traditional observation method. Taking three provincial capital cities （Shenyang, Changchun, Harbin） in Northeast Chi- na as examples, this study examined two critical phenology parameters （ start of growing season, and end of growing season） in the buffer zones within 20 km from these urban areas, which were calculated from time series MODIS NDVI images using Savitzky-Golay filtering and segmented Gaussian method. Changes of muhi-year mean parameters along the urban-rural gradients in rela- tion to land surface temperature and forest coverage were analyzed. The results show that areas closer to urban sites tend to have earlier start of growing season, later end of growing season, and greater variability. Along the urban-rural gradients, 1 ~C increase of land surface temperature in spring and last winter leads to an advance in start of growing season by 6-31 days, while 1 ℃ in- crease of land surface temperature in summer and autumn leads to a delay in end of growing sea- son by 0.9-7.6 days. In some buffer zones, increase of forest coverage also contributes similar advances in start of growing season and delays in end of growing season.

关 键 词：植被物候 地表温度 林地盖度 城乡梯度 

分 类 号：Q948.1[生物学—植物学]